Excel_paper_prisma.xlsx

SPATIALLY FRACTIONATED RADIATION THERAPY (SFRT) FOR BULKY TUMORS: A SYSTEMATIC REVIEW ON THE EVOLUTION AND IMPACT OF TECHNIQUES Abstract Background: Conventional radiotherapy for bulky tumors is limited by normal tissue tolerance and the risk of toxicity. Spatially Fractionated Radiation Therapy (SFRT), including techniques like GRID and Lattice Radiotherapy (LRT), intentionally creates a heterogeneous dose distribution to overcome these limitations. This systematic review explores the evolution of SFRT, from its historical origins to the implementation of modern techniques, and evaluates its clinical and dosimetric outcomes. Methods: A systematic review was conducted by searching the MEDLINE database for studies published from January 2010 to June 2025. The search used keywords such as "Spatially Fractionated," "Lattice," and "GRID" combined with "radiotherapy". Articles in English that were case reports, case series, or prospective trials were included. Data on patient characteristics, tumor location, treatment intent, clinical response, and toxicity were extracted and analyzed. Results: A total of 27 studies, comprising 363 patients and 468 lesions, were included. Tumor locations were most frequently the thorax (37.8%) and abdomen (16.7%), with sarcomas (34.4%) and NSCLC (15.7%) being the most common histologies. The majority of treatments was done for palliative intent (194 cases). Overall, tumor shrinkage was observed in 80% of lesions, and symptom control was consistently favorable. Treatment-related toxicity was generally low, with most adverse events being Grade 1 or 2. Severe toxicities (Grade ≥3) were rare, emphasizing the importance of careful patient selection and planning. The analysis highlights a significant lack of standardization in dosimetric parameters, such as the valley-to-peak dose ratio (VPDR), across studies. Conclusion: The available data confirm the feasibility, safety, and clinical effectiveness of SFRT for treating bulky tumors, particularly for palliation and rapid symptom relief. While promising, the field is hampered by a lack of dosimetric standardization and prospective data. Future research should focus on establishing standardized protocols and exploring the potential synergy of SFRT with novel systemic therapies, such as immunotherapy, to maximize therapeutic benefit.